Revert "Update Blazor form validation samples"

[guardrex]

Reverts #662

[guardrex]

@oroztocil ... Mmmmmmmmmmm 🤔 .... I'm trying to sort out how we'll handle a problem that has arisen with your samples PR.

The sample named "BlazorSample_BlazorWebApp" is the BWA sample app providing code to Blazor articles. The sample here isn't a complete copy/update of the 10.0 sample with added/updated validation code. It just has the new bits in it for validation.

I think there are two ways that we can proceed ...

• We can leave things as they stand ... leave what you did in place ... and I'll circle around after 11.0 GA to update the sample with the rest of the code that it needs.
• We revert your PR and set up the 11.0 sample now.

Mmmmmmmmmmm 🤔 ........... let's close this and not revert. I'd rather just take it on myself. You're busy. I'm the docs guy! 😆 I'll bring in the rest of the bits when the time comes.